Field of the Invention
The present invention relates to a pipe joint for connecting a tube through which a fluid is introduced and discharged, for example.
Description of the Related Art
Heretofore, a pipe joint has been used for connecting a tube to a fluid pressure device such as a cylinder or the like.
For example, the pipe joint disclosed in Japanese Patent No. 4016199 has a substantially cylindrical body. In the interior of the body, there are provided a substantially cylindrical sleeve that guides a tube along an axial direction, an annular packing for retaining an airtight condition between the body and the tube, a substantially cylindrical chuck for retaining the tube in the body, an engagement member for fixing the chuck in the interior of the body, and a release bush for facilitating separation and detachment of the chuck from the tube when the tube is taken out from the body.
In such a pipe joint, the chuck includes an inclined section, which is gradually expanded in diameter in a radial outward direction from one end side toward another end side of the chuck, an expanded diameter portion that extends substantially in parallel with an inner circumferential surface of the body, and a planar surface section, which is folded toward an inner circumferential side roughly perpendicular with respect to the expanded diameter portion.
On the other end side of the chuck, the distal end of the planar surface portion projects inwardly and is inclined at a predetermined angle, so as to be capable of piercing the outer circumferential surface of the tube. More specifically, the distal end of the planar surface portion functions as an engagement pawl for engaging the tube in the interior of the body.
On the other hand, on the planar surface portion in the vicinity of the engagement pawl, a recess is provided, which is formed in a curved shape curving toward one end of the chuck. When the engagement pawl is made to pierce the outer circumferential surface of the tube, a portion of the outer circumferential surface of the tube enters inside the recess. The portion of the outer circumferential surface of the tube abuts against an inner wall surface of the recess, whereby the tube is prevented from entering further into the recess by the inner wall surface thereof. Owing thereto, the amount by which the engagement pawl pierces with respect to the tube, i.e., the depth at which the engagement pawl is made to pierce into the tube, is restricted to a predetermined length (see Japanese Patent No. 4016199).